Hepatitis viral infection is one of the major causes of hepatitis. Currently, at least 8 different hepatitis viruses including the A, B, C, D, E, F, G and cryptogenic hepatitis viruses, are believed to exist. Of them, hepatitis B virus (HBV, a hepadnavirus) and hepatitis C virus (HCV, a flavivirus) lead to the greatest public health problem in industrialized countries. Hepatitis viral infection is also highly related to liver fibrosis/cirrhosis, liver cancer (hepatocellular carcinoma, HCC), liver failure and death.
In 2006, Chen C J et al. reported after 11.4 years following-up of 3,653 hepatitis B carriers that the incidence of liver cancer is highly related to hepatitis B DNA virus titer (Chen C J et al., Risk of Hepatocellular Carcinoma Across a Biological Gradient of Serum Hepatitis B Virus DNA Level, JAMA. 2006;295(1):65-73.) Therefore, reducing the virus DNA of hepatitis B carriers is the most important issue in management of these patients. Unfortunately, there are few effective treatments for hepatitis viral infection. For hepatitis B, anti-viral medicine includes adefovir (Hepsera®), entecavir (Baraclude®), lamivudine (Epivir-HBV®, Heptovir®, Heptodin®), Telbivudine (Tyzeka®) and tenofovir (Viread®). They reduce the ability of the virus to reproduce in the body of the patients and give the liver a chance to heal itself. However, these drugs are not a cure for hepatitis B even though they do reduce the damage caused by the virus. Furthermore, they are needed to be long term use even whole life. For hepatitis C, pegylated interferon or pegylated interferon with ribavirin has been used to treat the disease, the therapeutic efficacy of which are about 40-60%. However, pegylated interferon has unpleasant side effects in many people, such as general weakness, nausea, vomiting and bone marrow suppression. These side effects are so severe that many of the patients cannot continue taking the medication. Overall, these conventional treatments have not been shown to be particularly effective and most are accompanied by significant side effects.
There is a continued need for an effective treatment of hepatitis viral infection, particularly effective in reducing viral titer in a subject infected with a hepatitis virus.